The last sentence is the real issue. Where do you make the improvement? You're not replacing Vlad, Bo, Springer, Varsho, Kirk/Jansen. That's your core group at least through 2024. After that you have a group of impending free agents. They currently rank 2nd (Chapman), 3rd (KK), 4th (Merrifield), and 9th (Belt) on the team in WAR, and Belt ranks 3rd in wRC+ on the team, so it's not like any of them make sense to move or improve on either. The only thing I can think of is moving Varsho back to CF full time and finding a LF (trade KK for whatever piece you can get), but that's about it. Maybe there's a DH with more power than Belt has shown so far who makes more sense on this team, but he's still one of the best hitters on the team at the moment. Getting rid of the hitting coach and making some fundamental changes in player development has to be considered at this point. The lack of power up and down the lineup and organization as a whole (other than Orelvis in the minors) is mind boggling.
I tend to agree with not touching the system at the deadline. It's in a bad enough spot as it is, and this is not the roster that anyone should be doubling down on. Stand pat, live with the consequences (either miss the playoffs or hope for a Philly 2022 run), and go from there.